Featured Research

The Ribbed Mediterranean Limpet is one of the most endangered invertebrates of the Mediterranean Sea and is classed as being in danger of extinction. Researchers have discovered their reproductive strategy, consisting in changing sex from male to female and vice versa, which improves their ability to adapt to changes in their environment.

The Ribbed Mediterranean Limpet is one of the most endangered invertebrates of the Mediterranean Sea and is classed as being in danger of extinction. Researchers at the Spanish National Museum of Natural Sciences have discovered their reproductive strategy, consisting in changing sex from male to female and vice versa, which improves their ability to adapt to changes in their environment.

Related Articles

The Ribbed Mediterranean Limpet, Patella ferruginea, shares the unfortunate privilege of being included in the Spanish Catalogue of Endangered Species, together with other better known species such as the Iberian Lynx and the Imperial Eagle, under the maximum protection category, 'in danger of extinction'.

This is why a National Strategy was formed in 2008 for this invertebrate, commonly known as the ribbed limpet, for the conservation of the species. Fines for fishing for shellfish with this limpet range between 60,000 and 300,000 euros.

"One of the problems involved in the recovery of the Patella ferruginea is the lack of knowledge regarding basic aspects of its biology. This is the first time we have encountered this part of its reproductive strategy on an experimental basis," Javier Guallart, main author of the project and researcher at the Spanish National Museum of Natural Science, said.

The lack of biological knowledge surrounding the species is not unusual, given that the species is so endangered that there are only a few natural colonies left good enough to carry out the research projects. One of the most important colonies of the whole area in which they are located is the Spanish archipelago of the Chafarinas Islands opposite the coast of North Africa..

A team led by Guallart has spent six years travelling to this area to conduct research to explore one of the most essential aspects of the species' biology; its method of reproduction.

"Sexing" limpets is a complicated task

According to the scientist, the ribbed limpet had until now been believed to be a protandric hermaphrodite species. "As a reproductive strategy, this term means that youngsters, when they reach sexual maturity, do so as males and then, at some point during their vital cycle, change sex and become females."

This occurs often in molluscs and, in particular, in limpets. However, this conclusion has normally been based on indirect information. "For example, it is based on the fact that smaller specimens tend to be male and larger ones tend to be female," adds Guallart.

In order to confirm that they really do change sex, in 2006 a complex task began, involving sexing a number of specimens and returning to do it again a year later, during the next reproductive period (this species only reproduces once a year), to check whether they had changed sex.

"This may seem simple, but it is not. Sexing specimens means separating them from the substratum during the time of the year in which they are mature, between October and November, handling them and performing a small biopsy with a syringe to take a small sample of gonad in order to establish the sex according to the sample extracted (oocytes or sperm)," outlines the author.

The specimens were then returned to the coast, in the same place they were captured and this was done so they could adhere to the substratum, enabling them to continue with their way of life.

Also, given that it is a highly protected species, the death rate related to this handling operation had to be minimised which, as outlined in the article, has been achieved by following a protocol that was designed and tested for this purpose.

Females also change sex

In 2007 we discovered that a specimen previously sexed as male in 2006 was now a female, which meant this was the first direct and unprecedented proof of a sex change in the Patella ferruginea.

The work carried out between 2007 and 2008 also brought about further developments. On the one hand, it was confirmed that a number of specimens previously sexed as male were now females and a new unusual development was unearthed: a female had become a male between consecutive reproductive periods.

"The results obtained were fascinating. This reverse sex change from female to male was something anecdotally described for a species of limpet. During subsequent periods, between 2010 and 2011, we discovered that this was not an isolated case; a whole new approach to the method of reproduction of this protected species, which helps it to survive," stated the scientist. When and why the sex change occurs in each case is yet to be explained.

Knowing the main biological parameters of endangered species such as this one is vital in order to implement any strategy aimed at their conservation and recovery. "There is still a long way to go," reiterated Guallart.

Story Source:

The above story is based on materials provided by Plataforma SINC. Note: Materials may be edited for content and length.

More From ScienceDaily

More Plants & Animals News

Featured Research

Mar. 3, 2015  Two of the four known groups of human AIDS viruses (HIV-1 groups O and P) have originated in western lowland gorillas, according to new research. The scientists conducted a comprehensive survey of ... full story

Mar. 3, 2015  Methane emissions are strongly reduced in lakes with anoxic bottom waters. But – contrary to what has previously been assumed – methane removal is not always due to archaea or anaerobic bacteria. ... full story

Mar. 2, 2015  For the first time, researchers have produced a 3-D image revealing part of the inner structure of an intact, infectious virus, using a unique X-ray laser. The virus, called Mimivirus, is in a ... full story

Mar. 2, 2015  In the first study of its kind since the 1920s, rats in New York City were found to carry a flea species capable of transmitting plague pathogens. Among them: 500-plus Oriental rat fleas, notorious ... full story

Mar. 2, 2015  What do a human colon, septic tank, copper nanoparticles and zebrafish have in common? They were the key components used by researchers to study the impact copper nanoparticles, which are found in ... full story

Mar. 2, 2015  You might resemble or act more like your mother, but a novel research study reveals that mammals are genetically more like their dads. Specifically, the research shows that although we inherit equal ... full story

Mar. 2, 2015  Researchers have examined the association of nut and peanut consumption with mortality among low-income and racially diverse populations and found that intake of peanuts was associated with fewer ... full story

Mar. 2, 2015  Hungry, plant-eating insects may limit the ability of forests to take up elevated levels of carbon dioxide in the atmosphere, reducing their capacity to slow human-driven climate change, a new study ... full story

Mar. 2, 2015  A higher intake by postmenopausal women of the natural antioxidant lycopene, found in foods like tomatoes, watermelon and papaya, may lower the risk of renal cell carcinoma, a type of kidney cancer, ... full story

Mar. 2, 2015  Researchers have characterized the gut microbiome of honey bee queens. This is the first thorough census of the gut microbiome -- which consists of all the microorganisms that live in the gut of the ... full story

Zookeepers Copy Animal Poses In Hilarious Viral Photos

Buzz60 (Mar. 2, 2015)  Zookeepers at the Symbio Wildlife Park in Helensburgh, Australia decided to take some of their favorite animal photos and recreate them by posing just like the animals. Jen Markham (@jenmarkham) has the story.
Video provided by Buzz60

Related Stories

Feb. 17, 2015  Limpet teeth might be the strongest natural material known to humans, a new study has found. Limpets -- small aquatic snail-like creatures with conical shells -- have teeth with biological structures ... full story

May 29, 2014  Deep-sea limpets are conches with shells about 1 cm long. They have been confirmed to live in the long, narrow seabed known as the Okinawa Trough, located at an average of depth of 1000 meters and ... full story

Oct. 21, 2013  The genetic diversity within the immune system of giant panda is relatively high, according to an analysis that suggests they may be better suited to adapt to the changing environment than was ... full story

May 3, 2013  The Saharan cousin of Mediterranean olive trees remains largely unknown. However, this subspecies (called the Laperinne's olive tree) is of great interest for several reasons. Researchers have ... full story

July 26, 2012  Until now it was thought that fin whales in the Strait of Gibraltar and the Alboran Sea made up part of the distribution of this species of whale in the Mediterranean. However, scientists have just ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.